Modern turn insulation for stator windings with form-wound coils, in high-voltage rotating machines

It has been shown that, for the safe, reliable operation of high-voltage rotating electrical machines, the turn insulation of stator windings composed of form wound coils is of prime importance. It is highly important, not only to select the proper insulation dimensions for the machine type, but also to use the proper materials and to integrate them with the overall insulation system. The optimum selections can be made only on the basis of long-term test results. Many tests made over a long period of time have shown the following insulation types to be suitable: (1) heat-resistant enamels combined with spun-glass-fiber wrapping (only to rated voltage up to about 7 kV); (2) taping with one or more layers of micatape combinations; and (3) heat-resistant enamels applied with micatape combinations